Optical probe accessory device for use in in vivo diagnostic procedures

ABSTRACT

The present invention recognizes that optical probes function both as medical access devices and as instruments which collect complex optical data. The invention provides an optical probe accessory device which can access luminal spaces within the body of a patient without sacrificing the quality of optical data obtained. The accessory device further comprises either, singly, or in combination, selectable features or options which optimize light transmission, maximize patient comfort, and provide single-use capabilities.

RELATED APPLICATIONS

The application claims priority to U.S. Provisional Application Ser. No.60/138,235, filed on Jun. 9, 1999 and is also a continuation-in part ofU.S. patent application Ser. No. 09/481,762, filed Jan. 11, 2000, whichclaims priority to U.S. Provisional Application Ser. No. 60/115,373,filed Jan. 11, 1999, and is a continuation-in-part of U.S. patentapplication Ser. No. 09/241,806, filed Feb. 2, 1999, which is acontinuation-in-part of U.S. patent application Ser. No. 08/782,936,filed Jan. 13, 1997. The entirety of these applications is incorporatedby reference.

FIELD OF THE INVENTION

The invention relates to an accessory device for an optical probe foruse in in vivo diagnostic procedures. The accessory device provides anoptimal optical path for light from an optical probe while minimizingpatient discomfort. The accessory device features optional selectableelements to enhance its versatility in in vivo diagnostic procedures.

BACKGROUND OF THE INVENTION

The early detection of disease increases the chance for successfultherapeutic intervention. Non-invasive optical diagnostic devices whichdetect changes in the biochemical and structural features of tissuesprovide tools to detect the early stages of disease (e.g., cancer). Anoptical device for detecting tissue features typically comprises aconsole unit which includes a light source, a detector, electronics, anda computer, in communication with an optical probe through which lightis transmitted to and from a tissue. The optical probe can be the end ofa fiber optic cable or can contain complex optical elements intended toshape an output light beam from an optical source into a desiredgeometry.

Optical probes coupled to endoscopic devices have been used to obtaintissue-specific information from patients. Representative organs whichcan be characterized using an endoscopic approach include the colon,uterus, bladder, and stomach. Fluorescence spectroscopy using endoscopicoptical probes can distinguish between cancerous and precancerous tissuein these organs. However, the development of optical probes for clinicaluse has been hampered due to the difficulty of miniaturizing the opticalelements necessary for the collection of optical data. Additionalconstraints arise because an optical probe, like any medical accessdevice, must be decontaminated and sterilized prior to reuse. Thedelicate construction of light directing and focussing elements withinthe optical probe generally make it difficult, if not impossible, tosterilize the probe.

Because it is generally not economical to discard an optical probe aftera single use, it is desirable to provide an accessory device which actsas a shield between the illumination optics of the optical probe and thetissue being analyzed. While it is generally known in the art to equip amedical device with a protective barrier or sheath to provide a coverfor the device, it is desirable to provide an accessory device for anoptical probe which serves more than a mere barrier function, but whichcomplements the function of the optical probe. Accordingly, the presentinvention provides an accessory device for an optical probe whichcomprises multiple optional features to enhance the versatility of thedevice in in vivo diagnostic procedures.

SUMMARY OF THE INVENTION

The invention recognizes that optical probes function both as medicalaccess devices and as instruments which collect complex optical data.The invention provides an optical probe accessory device which accessesluminal spaces within the body of a patient without sacrificing thequality of optical data obtained. The accessory device further compriseseither, singly, or in combination, selectable features which optimizelight transmission, maximize patient comfort, and provide single-usecapabilities.

In one aspect of the invention, an accessory device for an optical probeis provided which creates an optimal light path between the opticalprobe and a target tissue. Optional optical elements are provided whichenhance the light transmitting and light receiving functions of theprobe. In one embodiment, an accessory device comprises optical elementswhich create an optical waveguide to improve optical data collection bythe probe. In this embodiment, the accessory device includes a windowwhich functions as an objective for the optical probe's illuminationelements. In other embodiments of the invention, the window is coatedwith anti-fog and/or anti-glare agents to maximize the passage ofdiagnostic light to and from the probe. In still other embodiments, theaccessory device is adapted to function with an optical probe whichcomprises a plurality of optical fibers and the accessory devicecomprises a plurality of openings sized to accept a plurality of lighttransmitting fibers from the optical probe.

By acting as an intermediate between the optical probe and the targettissue being analyzed, the accessory device is not subject to the samedesign constraints as the optical probe (i.e., does not have to be acertain minimum size to accommodate a plurality of optical elements).Accordingly, in one aspect of the invention, the accessory device can betailored to conform to a particular body lumen being accessed (e.g., inone embodiment, the cervix, in another embodiment, an ear canal).

For example, an optical probe accessory device which comprises, at leastin portion, a flexible material which conforms to the shape of a bodyspace being accessed is contemplated by the present invention. Theflexible portion provides a shield between the tissue being assayed bythe optical probe and the probe itself. In another embodiment, a segmentof the flexible portion conforms to an end of the optical probe bearingillumination optics, protecting the illumination optics of the probefrom bodily fluids while shielding the patient from contaminants. Instill another embodiment, the flexible nature of the accessory deviceallows it to be rolled up before and after use with the probe.

In another aspect of the invention, the attachment device is asingle-use, disposable device, allowing the optical probe to be usedmultiple times without transmitting disease from one patient to another.In this embodiment, to maximize the attachment device's capacity toprotect patients from contamination, the attachment device is crippled,either mechanically, or electronically, after a single use, so that anoptical probe will not function with an attachment device which has beenpreviously used.

For example, the accessory device comprises a body and an attachmentelement and is mechanically prevented from re-use. In this embodiment,the attachment element attaches the accessory device to the probe anddetaches from the body of the accessory device when the accessory deviceis removed from the probe. The accessory device is unable to functionwithout the attachment element and so detachment of the accessory devicefrom the probe prevents its reuse. In one embodiment, the attachmentelement comprises a grasping element, such as a tab or a snap ring whichdetaches the attachment element from the body of the accessory device.In a further embodiment, the attachment element is separated from thebody of the accessory device by perforations and rupturing theperforations detaches the attachment element from the body of theaccessory device.

In yet another embodiment, a disposable, single-use accessory device foran optical probe comprises an electrical element rather than amechanical element which prevents its re-use in another patient. In oneembodiment, the accessory device comprises an electrical element bearingencoded information (e.g., identification information). In anotherembodiment, the electrical element is remotely programmable and theinformation contained within the electrical element can be altered bythe user.

In a further aspect of the present invention, a system is provided whichcomprises a processor and an electrical element reader. The electricalelement reader accesses information encoded in the electrical elementcarried by the accessory device and transmits a signal to the processorrelating to identification information carried by the electricalelement. The processor includes a memory which stores identificationinformation and which compares the stored information withidentification information encoded by the electrical element. Theprocessor transmits instructions based on whether or not a match isfound between identification information encoded in the electricalelement and identification information stored within the memory. If nomatch is found, the identification information encoded in the electricalelement is added to the memory.

The instructions transmitted by the processor control the actuation ofthe optical probe. For example, in one embodiment, the system includes alight source in communication with both the processor and the opticalprobe. Transmission of light from the light source to the probe reliesupon instructions received from the processor. In another embodiment,instructions from the processor can include particular operatingparameters relating to a tissue-specific diagnostic procedure (forexample, but not limited to the diagnosis of cervical cancer). Use of anaccessory device with an electrical element which identifies the deviceas one which is suited for accessing the cervix triggers the processorto implement operating parameters suited to the diagnosis of cervicalcancer. Thus, the system provides flexibility that allows the opticalprobe to be used with a variety of accessory devices in a variety ofdiagnostic procedures.

Any or all of the foregoing optional features (the optical features toenhance light transmission, minimally invasive, tissue-conformingstructural features, mechanical or electrical disabling elementsconferring single-use capabilities) can be combined to meet the needs ofa particular diagnostic procedure. Because of the modular nature of theoptical probe accessory device, the optical probe itself is not limitedfor use in a single diagnostic application but can be adapted for avariety of diagnostic applications.

The foregoing and other objects, aspects, features, and advantages ofthe invention will become apparent from the following description andfrom the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The objects and features of the invention can be better understood withreference to the following detailed description and accompanyingdrawings, in which like reference characters generally refer to the sameparts throughout the different views.

FIG. 1 shows a schematic representation of an accessory device for anoptical probe according to one embodiment comprising an optical windowlocated at an end of the device distal from the illumination optics ofan optical probe.

FIGS. 2A and 2B show a schematic representation of an accessory deviceaccording to one embodiment comprising a single side-looking window.FIG. 2A shows a side view of such a device. FIG. 2B shows a top view.

FIG. 3 shows a schematic representation of a single use accessory probeaccording to one embodiment comprising a sectional transparent window.

FIG. 4 shows a schematic representation of a single-use accessory deviceaccording to one embodiment comprising a flexible tear-away sheath.

FIG. 5 shows a single-use accessory device according to one embodimentof the invention comprising an electrical element for encodingidentification information.

FIGS. 6A-C show schematic representations of accessory devices foroptical probes marked with identifying information in the form of a barcode. FIG. 6A shows an accessory device comprising a bar code on theside of the device. FIGS. 6B and C show an embodiment of the inventionin which the bar code is placed on an optical window which forms the endof the device distal to the illumination optics of the optical probe.FIG. 6A shows a view of the end of the device bearing the bar code. FIG.6C shows a view of the side of the device.

DETAILED DESCRIPTION

Because an accessory device according to the invention complements thefunction of an optical probe such accessory devices provide more thanmerely a sheath for an optical probe. An accessory device of theinvention comprises a number of optional features which a user canselect in optimizing the accessory device to suit a particularapplication. Any or all of these options can be present in an accessorydevice according to the invention. Because of the many permutations ofaccessory devices which can be designed according to the invention, theoptical probe itself acquires more versatility and can be used in avariety of diagnostic settings. It will be apparent to those of skill inthe art after reading this disclosure that other options canadditionally be provided, and such options are encompassed within thescope of the invention. All that is required to practice the presentinvention, is that the accessory device permit optical data collectionby an optical probe without obstruction. A number of preferred featuresof a device of the invention is discussed below. These may be usedsingly or in combination with each other or with other probe featuresknown in the art. The skilled artisan appreciates that numerous otherfeatures may be included in a device of the invention, either alone orin combination.

Option 1. Maximal Light Transmission

In one aspect of the invention, the accessory device provides additionaloptical features to enhance the transmission of light from the opticalprobe to the tissue and from the tissue to the optical probe. Accordingto this aspect of the invention, the user selects optical features thatare for the accessory device that are compatible with the operationparameters of the optical probe.

In practice, the accessory device is fabricated using material which hasa high optical transmission over the spectral bandwidth of operation ofthe probe. For example, for some probes, obtaining an image by the probeis not as important as obtaining a very high signal-to-noise ratio froman optical response in spectral regions that do not overlap, or onlypartially overlap, the visible region of the spectrum. That is, theinclusion of features to ensure adequate performance of the optics tocreate a visual image of the sample may degrade the performance of thedevice in collecting acceptable optical signals such as fluorescence,Raman, or reflectance spectra. In embodiments where image quality is notan issue, the portion of the accessory device actually transmitting anultraviolet (UV) excitation beam (e.g., the end of the device distal tothe probe) can be made of a very thin Teflon® or can comprise otherfluoroplastics such as THV-200P® (a TFE/HPF/VDF terfluoropolymer fromthe 3M® corporation). These plastics do not demonstrate a significantfluorescent response when irradiated with UV.

In some embodiments, the accessory device is used with an optical probewhich functions by directing light to a tissue and receiving at leastfluorescent light re-emitted from the tissue after absorption of theexcitation light, while in other embodiments, the accessory devicereceives scattered light from a target tissue, such as elastic scatteredlight (e.g. reflectance spectroscopy) or inelastic scattered light(e.g., as in Raman spectroscopy applications). In these embodiments, thelight being directed back to the probe provides diagnostic informationrelating to the chemical/structural features of a tissue being analyzedrather than its morphological features. An accessory device used inthese applications is made of materials which provide minimalinterference with the light being directed back towards the probe. In apreferred embodiment, the accessory device comprises a low-fluorescingplastic and has high optical transmission through the ultraviolet andvisible spectral regions from 300 nm to 750 nm.

In other embodiments, where imaging is a function of the probe, anaccessory device is provided which does not fluoresce when illuminatedby a laser or other light source and has a sufficiently large apertureor opening to collect low levels of light emitted during fluorescence ofsome samples such as tissue, good modulation transfer function for goodimage transmission, and/or a lack of color tint to preserve spectralaccuracy. The accessory device can be fabricated from materialincluding, but not limited to, UVT acrylic or amorphous polyolefin(e.g., Zeonex®, Nippon Zeon CO., Ltd.) and the like. The skilled artisancan recognize and identify equivalent materials using routineexperimentation and routine testing.

The type of optical probe, and hence the type of accessory device used,will depend upon the particular diagnostic application required. Forexample, in diagnosing cervical tissue pathologies, in some instances itis desirable to obtain both imaging and non-imaging optical information.This combination of modalities is important when spatial location ofbiopsy sites is the output of the optical device. In this embodiment, anaccessory device should be selected which creates minimal interferencewith the spectroscopic functions of the device, and has good imagingcapability to locate specific tissue sites. However, when theapplication is ASCUS Triage (Atypical Squamous Cells of UndeterminedSignificance Triage), non-imaging information is more important, becausedetermining the location of the abnormal tissue is not necessary. Here,an accessory device can be used which is not suited for imagingpurposes. In a third instance, the optical probe can be used as anadjunct to a standard pap smear test. In this embodiment, a non-imagingdevice is suitable.

The present invention also contemplates that the optical features of theaccessory device include optical elements which complement the functionof the optical probe. In one embodiment, the accessory device includes aflat window which permits passage of diagnostic light to and from theoptical probe without distortion. Window materials include, but are notlimited to, cast or molded polymethylmetacrylate (PMMA) and othermaterials which provide no significant fluorescence in response to anexcitation beam. By way on non-limiting examples, polystyrene orpolycarbonate are two such materials. The placement of the window on theaccessory device is selected to optimize the collection of light from atissue being analyzed. In one embodiment, shown in FIG. 1, the window 11is at the end of the accessory body 10 most distal from the probe. Inanother preferred embodiment, shown in FIGS. 2A-B and FIG. 3, the windowis provided on the side of the accessory device, giving the opportunityto gather optical information from the side as the device is moved alongor through a sample. The window can be configured in a variety ofshapes. In the embodiment shown in FIGS. 2A and 2, the accessory devicecomprises a circular window 13. In the embodiment shown in FIG. 3, thewindow is a transparent section 15 of the accessory device.

In another preferred device, the window is fastened onto the end of acylindrical- or toroidal-shaped ring segment that is press-fitted ontothe accessory device, forming an annular lens which functions as anobjective for the optical probe's illumination elements. The wallthickness of the ring segment on which the window/lens sits is designedto allow the accessory device to act as an optical waveguide to directlight onto target tissues for better visualization or data collection.In one embodiment of the invention, the wall thickness of the ringsegment is between about 0.5 mm and 2.0 mm. The window itself can form alens, or alternatively, a lens can be added to the window as a separateelement. For example, the window can be segmented so that a portion ofthe structure is flat (i.e., optically passive), while other portionsare curved (i.e., forming lens segments).

In another accessory device contemplated by the invention, a deliveryapparatus is operably connected to the window for dispensing a fluidwhich has an index of refraction matching the window or other exposedoptical elements in the accessory device and/or optical probe. Deliverydevices encompassed within the scope of the invention include a bead orother container residing in a space defined by the ring segment whichcan be caused to break and discharge its fluid. Fluid from the deliverydevice spreads downward by capillary force to fill the space betweenoptical elements in the accessory device (e.g., such as the windowitself) and the optical probe. In another embodiment, the window iscoated with an anti-fog agent or an anti-glare agent. In still a furtherembodiment, the accessory device is provided with a flexible sleevewhich covers the window and serves a protective function.

The accessory device of the present invention can also be adapted toinclude other optical elements to facilitate the acquisition ofdiagnostic data, such as filters, polarizers, or light reflectingelements. For example, in one embodiment of the invention, the distalend of the accessory device includes a reflecting element such as anintegral faceted mirror. In a further embodiment, the reflecting elementis in the shape of a cone which has a half angle of 45 degrees. A lightbeam impinging on one of the facets of the reflecting element will bereflected at a 90 degree angle to the incident light causing it to beemitted laterally from the distal end of the accessory device, allowinglight to be efficiently directed to the target tissue within the lumenthe accessory device is accessing. A light-focusing element canadditionally be provided in optical communication with the reflectingelement in order to focus light beams appropriately on the targettissue. In still further embodiments of the invention, reflectingelements are provided within the body of the accessory device in opticalcommunication with a window. In the embodiment of the invention shown inFIG. 2B, the reflective element is a reflective planar surface 14. Inthe embodiment of the invention shown in FIG. 3, the reflecting elementis a conical surface which directs light from the optical probe towardsthe transparent sectional window 15. It should be apparent to those askill in the art that a variety of shapes of reflecting surfaces can beprovided and positioned to optimize the light path from the opticalprobe to the window of the accessory device.

In embodiments of the invention where the optical probe being used withthe accessory device comprises a plurality of optical fibers, areflecting element can be provided whose number of facets correspond tothe number of excitation fibers in the probe, creating an optimal lightpath between the target tissue and light from the optical probe throughthe accessory device. In this embodiment, the accessory device can alsobe configured to attach to the probe in way that further optimizes thislight path. For example, in one preferred embodiment, the accessorydevice is fitted onto the probe via a connecting ring which comprisesopenings designed to adapt to a particular configuration of opticalfibers (e.g., bundled or spaced). Attachment of the probe to theaccessory device can only be achieved by correctly aligning opticalfibers with appropriate regions in the accessory device. In oneinstance, the optical probe comprises a plurality of pins which fit intoholes in the connecting ring of the accessory device only when theaccessory device is positioned in a specific orientation, ensuring theproper orientation of the optical probe with respect to the accessorydevice.

Additionally, the accessory device can be adapted to provide a lightsource for evenly illuminating a tissue being visualized. In oneembodiment, the accessory device includes an illuminating light sourcepositioned around the circumference of the accessory device. Theilluminating light source can be an integral part of the device or canbe snapped on by a ring mechanism.

In applications where visible marking or tagging specific regions of thesample is necessary or important, the accessory device is provided witha dispenser capable of directing a marking fluid toward the sample. Thefluid can be applied to localized regions of the sample for identifyingselected regions, or it can be dispensed over a broad region of thesample, as a bath or wash. The purpose of the bath or wash may be toaffect chemical changes in the sample to aid in the identification ofsubstances in or characteristics of the sample. For example, in opticaldetection of pre-cancerous lesions of the cervix, the application of amild acetic acid wash increases the contrast and visibility of theregions of suspicious lesions.

Other types of fluids that can be used to enhance visualization of thesample, include hypertonic, hypotonic, hyperosmotic, and hypo-osmoticsolutions. Hyper- or hypo-osmotic solutions can be generated in a numberof ways, such as by using distilled water, either alone, or incombination with ionic or nonionic molecular constituents. Varying thehydrogen ion concentration of a fluid (e.g., pH) can generate additionalvisualization-enhancing agents. Dye solutions can also be applied suchas, for example, Lugol's iodine, toluidine blue or methylene blue, andothers.

Option 2. Minimal Invasiveness, Tissue-Conforming Structure

The accessory device can be designed to conform to a particular lumenbeing accessed, thus minimizing the invasive effect of the accessorydevice. In one embodiment, the accessory device comprises a flexibleportion which provides a shield between the tissue being assayed and theoptical probe while at the same time maximizing patient comfort byadapting itself to any space being accessed by the device. In oneembodiment, the flexible accessory device can be in the form of aninflatable balloon into which a fluid (e.g., an index-matching fluid) isinserted to partially inflate the structure. Balloons can be made fromcompliant materials, such as polyethylene, latex (natural or synthetic),polyurethane, and silicone, or non-compliant materials, such aspolyethylene terephthalate (PET).

When brought into contact with the tissue, the flexible accessory devicedistributes the contact pressure of the device evenly over the entirecontact surface (such as a body lumen), while the index-matching fluidprovides good optical communication with the tissue. In anotherembodiment, the flexible portion also conforms to the end of the opticalprobe bearing illumination optics, shielding the illumination optics ofthe probe from body fluids, while simultaneously shielding the patientfrom contamination by the probe. In this embodiment of the invention,the accessory device comprises, at least in portion, a shrink-fittedmaterial (e.g., which can be shrunk using heat). A heating element (suchas, but not limited to, a resister) can be included in the shrink-fittedmaterial such that shrinkage is triggered when a voltage is applied tothe resistor. Alternatively, the material can be shrunk using a heatingdevice such as a hand-held hairdryer. Because of the flexible nature ofthe accessory device, it can be packaged in a rolled-up state (e.g., ina sterile wrapper) to be unrolled over the optical probe when it isready to be used.

In one embodiment, the accessory device comprises both a flexibleportion and a rigid tip portion. The length and diameter of the tipportion is selected to be optimal for accessing a particular body lumenand to provide for the effective transmission of diagnostic light fromthe optical probe, while the flexible portion of the accessory device isconformed like a skirt and is proximal to the end of the optical probebearing illumination optics. The flared and flexible nature of theflexible portion minimizes patient discomfort from the entry of anyportion of the optical probe itself into the body cavity being accessed.The flexible material and the rigid portion of the accessory device canbe molded as a single unit or can be molded separately and connectedtogether.

The optical probe accessory device according to the present inventioncan also be designed for a particular anatomic application, e.g., forobtaining information relating to tissue features of thegastrointestinal tract, the urinary tract, the peritoneal cavity, thethorax, ear canal, and the female reproductive tract. Other organssuitable for endoscopic or percutaneous access will be apparent to thoseof ordinary skill in the art. In each of these cases, the accessorydevice is designed as a probe with a particular geometry adapted for thebody region towards which it is directed. In one embodiment of theinvention, an accessory device is provided for use with an optical probeused in the cervix. In this embodiment, the accessory device covers thesides of the probe that encounters the vaginal walls and additionallycovers the end of the optical probe comprising illumination optics. In afurther embodiment, the accessory device is designed to at leastpartially cover an optical probe and is capable of passing, with theprobe, through a distal aperture of an endoscope. In this embodiment,the accessory device is accordingly limited in sized to conform to thedimensions of the body cavity being accessed and the dimensions of theendoscope.

In still other embodiments of the invention, the accessory device isdesigned to transmit light from an optical probe to the surface of atissue which is not accessed through a lumen, for example, the skin, orbreast tissue, or tissue within an open surgical field.

Option 3. Single-Use Device

In accordance with the present invention, a single-use accessory deviceis provided for at least partially covering an optical probe. In oneembodiment, the accessory device entirely covers the probe, while inanother embodiment, the accessory device covers or shield those parts ofthe probe adapted for contact with a body tissue of a patient. Asdefined herein, the term “single-use” is understood to mean that the useof the accessory device is restricted to use with a single patient.However, in some embodiments, use can be confined to a single diagnosticmeasurement.

In one preferred embodiment according to this aspect of the invention,the accessory device comprises both a body and an attachment element forattaching the accessory device to the probe wherein the device ismechanically prevented from re-use. For example, the accessory devicecomprises a breakable element to allow for physical breakage of at leasta portion of the device upon removal from the optical probe. Theattachment element according to this embodiment includes at least onebreakable portion which must be broken in order to remove the accessorydevice from the probe. Breaking the breakable portion cripples theaccessory device, preventing its reattachment and re-use. In anotherembodiment, the breakable portion includes a grasping element, such as atab or snap ring, and grasping the grasping element results in breakingthe body of the accessory device from the attachment element. In stillanother embodiment, as shown in FIG. 4, the attachment element comprisesa flexible material 12 and the accessory device can only be detachedfrom the probe by tearing the flexible material 12, separating theattachment element portion of the accessory device from the bodyportion. Alternatively, the flexible element can comprise a weakenedmaterial, or breakpoint, where it joins to the body of the device (e.g.,perforations) to facilitate tearing. The breakpoint is more susceptibleto mechanical stress than the remaining portions of the device.

The attachment element can be mechanically attached to optical probe bya variety of mechanisms, including, but not limited, to a tab/slotmechanism (such as a tab on the attachment element fits into a slot onthe outside of the optical probe or visa versa), a magnetic attachmentmeans, a lock and pin mechanism, a band-latching mechanism, or a string.Other types of attachment mechanisms (such as fasteners, elastic bands,strings within the accessory device which can hook onto the probe,Velcro, adhesive, tapes, glues), including those which rely on mating aprotruding element (on the accessory device or the probe) to a recessedelement (on the probe or the accessory device) will doubtless beapparent to those of skill in the art, and are included within the scopeof the invention.

In another embodiment, the actual means of attachment of the attachmentelement is the breakable element in the device. For example, in oneembodiment, where the attachment element attaches to the probe by atab/slot mechanism, removal of the accessory device can only beperformed by breaking the tab off, thereby preventing the accessorydevice from being reattached. In another embodiment, where a protrudingmating element is provided on the accessory device to allow it to matewith a recessed element in the optical probe, the protruding matingelement is designed to tear along a tear line, or perforation, in theaccessory device upon mechanical stress (e.g., when the protrudingelement on the attachment element is disengaged from recessed element onthe surface of the optical probe), preventing the protruding matingelement from functioning in future.

In yet another embodiment of the invention, at least the attachmentelement of the device is made of a flexible material and a “cinch purse”string is provided to both secure the attachment element to the deviceand to provide a grasping element. In this embodiment, the string isattached to a breakable element so that pulling the string breaks thebreakable element and permits the flexible portion of the accessorydevice to be rolled over, away from the optical probe. Once thebreakable element is broken, the accessory device is unable to bereattached to the optical probe.

While the attachment element can attach directly to the optical probe,it can also attach through an intermediate interfacing element whichitself attaches to the probe (e.g., via a ring or a plastic connectingsleeve). In a further embodiment of the invention, the attachmentelement and the body of the accessory device are modules which can befitted together. Different types of interfacing elements can be used tointerface different types of attachment elements and bodies to differentoptical probes, allowing the user to select and combine differentdesired features of the accessory device with a particular kind ofoptical probe.

In another embodiment of the single-use option, the accessory device isprevented from reuse by degrading the optical quality of the accessorydevice after use. For example, coatings susceptible to ultravioletradiation, can be placed on the light-transmitting portion of theaccessory device. During proper use of the device, the coating issubjected to a sufficient quantity of ultraviolet radiation so that itbecomes at least partially opaque, preventing its reuse.

The invention also provides an accessory device which can be disabledafter use without physically altering the device, that is,electronically, for example. In one embodiment, an electrical contactbetween the accessory and the optical probe is provided. In thisembodiment, an electrical element is embedded within the accessorydevice which is capable of making electrical contact with the opticalprobe when the accessory device is properly affixed to the probe. Asdefined herein, the term “electrical element” encompasses both passiveelectrical elements (e.g., resistors, capacitors, inductors, diodes, andothers) and active electrical elements (e.g., transistors, integratedcircuits, such as microchips, and others). In one embodiment, after use,the optical probe delivers a current to the accessory device sufficientto destroy the electrical element, thus preventing reuse of theaccessory device.

In another embodiment, as shown in FIG. 5, the accessory device isprovided with an electrical element 17 bearing encoded information. Theelectrical element can be secured to the accessory device by insertionat a notch on the surface of the device, or alternatively, can be heldin place by a biocompatible adhesive (e.g., a cyanoacrylic adhesive) andcan additionally include electrical contact elements for making contactwith the probe.

In one embodiment of the invention, the electrical element 17 bearsencoded information relating to the identification of the accessorydevice. For example, the encoded information identifies the device asone which has already been used with the optical probe. In a furtherembodiment, the electrical element 17 includes encoded informationrelating a target tissue which is being analyzed. Additional informationencoded by the electrical element 17 includes, but is not limited to,time, present date, date of manufacture, materials used in construction,and the condition of the optical probe or the processing system usedwith the optical probe. Additionally, the electrical element 17 caninclude information regarding the intended use of the optical probe, andcan enable only certain modes of operation of the probe. As definedherein, an “operating mode” refers to either, or both, the input oroutput of the optical probe. In one embodiment, the operating mode is afunctioning or non-functioning state of the optical probe. In anotherembodiment, the operating mode is any of a plurality of input or outputstates of the device. For example, in one operating mode, the opticalprobe is directed to provide optical information relating to thelocation of a sample (e.g., a cancerous tissue) while in anotheroperating mode, the optical probe is directed to provide informationrelating only to a biochemical feature of a sample (e.g., the presenceor absence of fluorescence relating to a cancerous or precancerousstate), while in still another operating mode, both types of informationare provided.

Different types of electrical elements can be used. The electricalelement can be a programmable read-only memory chip (PROM). Theelectrical element can be remotely programmable. In another embodimentof the invention, the electrical element is an RFID (radiofrequencyidentification device) or another active seminconductor device.

Information within the electrical element can be passed on to aprocessor in communication with the optical probe through a electricalelement reader which accesses stored information in the electricalelement in a non-contacting manner. In one embodiment, the electricalelement reader is capable of receiving electromagnetic signals. Inanother embodiment, the electrical element reader is capable ofreceiving radiosignals from the electrical element.

When the electrical element reader is placed in a location in which itcan access stored identification information encoded in the electricalelement, the electrical element reader transfers this information to aprocessor to which the optical probe is operatively connected. Forexample, the electrical element reader can be either attachable to theoptical probe or an integral part of the optical probe itself, such thatthe reader has access to the electrical element as soon as the accessorydevice is attached to the optical probe. Information from the electricalelement is thus immediately transferred to the processor which providesinstructions to the probe to either enable it or prevent it fromfunctioning. In one embodiment, where the electrical element is an RFIDchip, the “reader” is a transponder for receiving radiosignals from theelectrical element.

In some applications, it is desirable to re-use the accessory device ifanother diagnostic test needs to be done with the same patient within ashort time of the first diagnostic test (e.g., where the probe has notbeen removed from the patient). In this embodiment, the electricalelement can be re-programmed or programmed with additional information,allowing the optical probe to function with the same accessory device.In certain embodiments of the invention, the electrical element readeris configured as an encoding device to conveniently change or addinformation stored within the electrical element.

As contemplated herein, processor includes a memory which comprisesidentification information identifying accessory devices that have beenused with the optical probe. If a match is found between theidentification information obtained by the electrical element reader andthe identification information within the memory, the processortransmits instructions to the optical probe which prevents it fromfunctioning. The instructions are then relayed to component(s) of anoptical diagnostic system of which the optical probe is a part. Forexample, the optical diagnostic system comprises a light source which isin optical communication with the optical probe. The presence of a matchbetween identification information encoded by the electrical element andidentification information within the memory of the processor preventslight from being transmitted from the light source to the optical probe.In another embodiment of the invention, the optical diagnostic systemcomprises an optical probe-locking device which prevents the probe frombeing moved (e.g., to position it within a patient) if a match is foundthus effectively preventing the probe from being used with the “wrong”accessory device. When no match is found between the information storedwithin the electrical element and information stored within the memory,the identification information relating to the electrical element isadded to the memory. In this way, subsequent use of the accessory devicewill result in instructions being sent to the probe which prevents itfrom operating.

In an alternative embodiment, the processor can transmit instructions tothe optical probe which allow it to function if a “correct” accessorydevice is used with the probe. In this embodiment, the processortransmits instructions to either the probe itself and/or to othercomponents of the optical diagnostic system when no match is foundbetween identification information encoded in the electrical element andthe identification information stored in the memory. The instructionsthen trigger the optical probe or other component of the opticaldiagnostic system to function (for example, light can be transmittedthrough the optical probe or a specific diagnostic application can berun in response to the instructions).

In another embodiment, the electrical element is encoded withidentification information which can only be read if the accessorydevice is positioned in a correct orientation with respect to theoptical probe (for example, in an orientation which maximizes lighttransmission from the probe to the accessory device). In thisembodiment, the processor will only transmit instructions to the opticalprobe to allow the probe to function if the accessory device ispositioned correctly.

Information other than identifying information can also be transmittedto the processor via the electrical element. For example, informationrelating to the “readiness” of the optical probe/accessory device can beprovided to the electrical element by sensors on the accessory device orthe optical probe which are responsive to the environment in which theaccessory device/and or probe is placed. The electrical element in turntransmits the information to the processor which can alter thefunctioning of the probe as appropriate.

The electrical element can further include information relating to thetarget tissue being analyzed. In this embodiment of the invention,information read by the electrical element reader triggers the processorto activate diagnostic programs unique to the analysis of thatparticular tissue. For example, the accessory device comprises aelectrical element identifying it as an accessory device used to accessthe cervix. When the processor receives this information from theelectrical element reader, the processor will access specific computerprogram product(s) (e.g., software applications) relating to thediagnosis of cervical tissue pathologies (e.g., cervical cancer) andwill activate particular data input or data display screens that relateto diagnosing these pathologies. In other embodiments, the electricalelement can include patient identifying information, includinginformation relating to a history of a particular disease (e.g., whetherthe patient has a family history of cervical cancer).

In certain embodiments, a particular type of accessory device ispreferred for a particular diagnostic application. In these embodiments,it is desirable to prevent an optical diagnostic system from functioningunless it is used with a suitable accessory device. In order to ensurethat the proper accessory device is used in its appropriate diagnosticapplication, the electrical element in the accessory device is encodedwith information indicating that it is suited for a particular use(s).When the processor accesses this information through the electricalelement reader, only a proper match between the use and the device willpermit the optical probe or other components of the optical system tofunction.

Although, non-physical means of crippling the accessory device after asingle use have been disclosed with reference to an electrical element,it should be apparent to those of skill in the art that a number ofdifferent types of feedback mechanisms can be incorporated into anoptical diagnostic system. In one embodiment, an optical probe isprovided which is equipped with a light emitting diode and an infraredsensor, while the accessory device is marked with a series of lines onone of its surfaces providing identification information. In thisembodiment, the optical probe sensor obtains information relating to theaccessory device's identification information and transfers thisinformation to the processor which sends instructions to the probe orother components of the system to enable or prevent the probe fromfunctioning with that particular accessory device.

Optical methods for communicating the usage history of the accessorydevice to the optical probe can also include bar codes. In oneembodiment as shown in FIG. 6A, a bar code 18 designed to be read byreflectance or fluorescence is fixed to the body of the accessorydevice. If it is placed on the side of the accessory device, a separatereader may be needed to scan the code. The lot number, intended use, andother pertinent information is contained in the code and interpreted bythe optical scanner. In another embodiment, shown in FIG. 6B, the code19 is fixed to a transparent part 20 of the accessory device. Thispermits the optical system itself to read the contents of the code 19prior to performing its measurement of the sample (e.g., tissue). Otheraccessory device marker and reader combinations will be apparent tothose of skill in the art, and are encompassed within the scope of theinvention.

As discussed above, any or all of the foregoing options can be combinedto create accessory devices suitable for particular diagnostic purposes.For example, an accessory device including optical elements can alsoinclude electrical and/or mechanical elements to disable the devise sothat it can only be used a single time. Devices with optical elementsand/or single-use devices can include the structural features that makean accessory device minimally invasive and/or tissue-conforming. Any andall of these combinations are encompassed within the scope of theinvention.

Variations, modifications, and other implementations of what isdescribed herein will occur to those of ordinary skill in the artwithout departing from the spirit and scope of the invention as claimed.Accordingly, the invention is to be defined not by the precedingillustrative description but instead by the spirit and scope of thefollowing claims.

1. An accessory device for an optical probe comprising a body and anattachment element for attaching the accessory device to the probe, saidattachment element detaching from the body of the accessory device whenthe accessory device is removed from the probe, thereby preventingre-use of the accessory device.
 2. The accessory device of claim 1,wherein said attachment element includes a grasping element and whereingrasping said grasping element detaches said attachment element from thebody of the accessory device.
 3. The accessory device of claim 2,wherein the grasping element is a tab or snap ring.
 4. The accessorydevice of claim 1, wherein the attachment element is conformable to anend of the probe bearing illumination optics.
 5. The accessory device ofclaim 4, wherein the attachment element is flexible and the body of theaccessory device is rigid.
 6. The accessory device of claim 1, whereinthe attachment element is separated from the body of the accessorydevice by perforations and wherein rupturing said perforations detachesthe attachment element from the body of the accessory device.
 7. Theaccessory device of claim 1, wherein at least a portion of the device ismade of a shrink-fitted material.
 8. The accessory device of claim 7,wherein the shrink-fitted material is shrinkable using heat.
 9. Theaccessory device of claim 7, wherein the accessory device can be rolledup before and after use with an optical probe. 10-41. (canceled)
 42. Theaccessory device of claim 1, wherein the attachment element isconfigured to prevent reattachment of the accessory device to the probeafter the accessory device is removed from the probe.
 43. An accessorydevice for an optical diagnostic system having an associated reader, theaccessory device comprising a marker capable of being read by the readerto thereby prevent re-use of the accessory device.
 44. The accessorydevice of claim 43, wherein the marker comprises a bar code.
 45. Theaccessory device of claim 43, wherein the marker comprises an RFID chip.46. The accessory device of claim 43, wherein the marker is capable ofbeing read by an optical sensor.
 47. The accessory device of claim 43,wherein the marker comprises encoded information.
 48. The accessorydevice of claim 47, wherein the encoded information comprisesidentification information.
 49. The accessory device of claim 43,wherein at least a portion of the accessory device provides a shieldbetween a contact surface and an optical probe.
 50. The accessory deviceof claim 49, wherein the optical probe is a part of the opticaldiagnostic system.
 51. The accessory device of claim 49, wherein theaccessory device is configured to prevent contact between a patient andthe optical probe.
 52. The accessory device of claim 49, wherein thecontact surface is a body lumen and wherein at least a portion of theaccessory device is configured to conform to the body lumen.
 53. Amethod for limiting re-use of an accessory device with an optical probein an optical diagnostic system, the method comprising the steps of:providing an accessory device comprising a marker; reading the marker toobtain information about the accessory device; and at least one of:disabling operation of the optical probe with the accessory device basedat least in part on the information, where the accessory device has beenpreviously used; and enabling operation of the optical probe with theaccessory device based at least in part on the information, where theaccessory device has not been previously used.
 54. The method of claim53, wherein at least a portion of the accessory device provides a shieldbetween a contact surface and the optical probe.
 55. The method of claim54, wherein the contact surface is a body lumen and wherein at least aportion of the accessory device conforms to the body lumen.
 56. Themethod of claim 53, wherein the information comprises identificationinformation about the accessory device.
 57. The method of claim 53,wherein the information comprises usage history of the accessory device.58. The method of claim 53, wherein the marker comprises a bar code. 59.The method of claim 53, wherein the marker comprises an RFID chip. 60.The method of claim 53, wherein the reading step comprises scanning themarker.
 61. The method of claim 53, wherein the method prevents re-useof the accessory device with the optical probe.